A customer holds an iPhone 6 (R) and iPhone 6 Plus after the phones went on sale at the Fifth Avenue Apple store in Manhattan, New York September 19, 2014. Credit: Reuters

Apple Inc. withdrew a faulty update to its latest operating system after some users of its new phones complained of call service disruptions, the latest in a series of glitches to mar the first week of iPhone 6 and 6 Plus sales.

Apple shares slid nearly 4 percent to $97.72 in early trading, to be the biggest drag on the Nasdaq Composite Index . At that price, the stock had lost all its gains since the launch of the latest iPhones and the company's market value declined by $24 billion.

"We apologize for the great inconvenience experienced by users," Apple spokeswoman Trudy Muller said in an email.

Apple said on its website it was working to prepare iOS 8.0.2 with a fix for the issue, and will release it in the next few days.

"I do believe this speaks to execution issues at Apple," said JMP Securities analyst Alex Gauna. "At the end of the day I believe this too shall pass, but we are noting with concern that the miscues pile up."

Users of the iPhone 6 and 6 Plus complained about a drop in cellular service and inability to use the fingerprint-reading Touch ID after updating to iOS 8.0.1.

Some users had complained of "sluggish Wi-Fi and dwindling battery life" after moving to iOS 8, Time magazine reported earlier this week.

The new phones also face criticism over their bendability, dubbed "bendgate." Social media and online forums have been abuzz with comments about how the new phones can bend when placed in back pockets or while wearing skinny jeans.

"It's not game over for Apple, but nor should we give them a pass on this," Gauna said.

Apple, which said on Monday it had shipped 10 million units of iPhone 6 and 6 Plus, did not comment on the issue.

On Thursday, it issued a step-by-step guide for users to reinstall iOS 8, launched last week, through the latest version of iTunes. The health app will not work for now and will be fixed in iOS 8.0.2, the company said.

Customers might, however, hope for replacements for their bent iPhones, depending on whether their devices passed an inspection, tech news website The Next Web reported, quoting an Apple support executive.

Cases of bent iPhones 5 and 5s had been reported in 2013 by Cult of Mac, a website that exclusively covers Apple.

Rival smartphone makers took digs at Apple's problems.

A Samsung Electronics advertisement showcased a bending phone against its own product, while BlackBerry CEO John Chen said: "I would challenge you guys to bend our Passport."